WASHINGTON — During President Donald Trump’s July call with Ukrainian president Volodymyr Zelensky — the one where the president asked for help finding damaging information on the Mueller probe and Joe Biden — Trump urged Zelensky to talk to two people: Rudy Giuliani and Attorney General Bill Barr.

So far, House Democrats’ impeachment investigation has focused heavily on the activities of the former, and not on the latter.

That Trump told Zelensky to talk to Barr and Giuliani made sense, even though one is the nation’s top law enforcement official and the other is not. Both men have been gathering information about the US counterintelligence probe into Russian interference in the 2016 election that morphed into special counsel Robert Mueller’s investigation — a probe Trump and his supporters have long tried to discredit — and sought help from foreign officials to do so.

Trump on Wednesday repeated his support for an investigation into the origins of the Russia probe, and told a reporter to ask Barr for details on the status of that.

“I don't know the details. I just know that our country is looking into the corruption of the 2016 election,” Trump said during a press conference with the Italian president. Asked about reports that Barr met with Italian officials about that investigation, Trump replied: “I don't know anything about the meeting but certainly it would be appropriate ... so you'll really have to ask Attorney General Barr, OK?"

While Giuliani’s travels to Ukraine and meetings with Ukrainian officials are well-documented by now, Barr has denied similar contacts. Despite Trump’s repeated invocations of the attorney general’s name, Barr has flown largely under the radar.

The congressional committees probing whether Trump committed impeachable offenses have issued subpoenas to Giuliani and his associates; they’ve yet to issue any subpoenas or requests for voluntary cooperation to Barr or the Justice Department, at least not that they’ve publicly announced. A spokesperson for the House Intelligence Committee declined to comment.

Former congressional and Justice Department lawyers who spoke with BuzzFeed News offered a few theories about why Democrats don’t seem as interested in the Justice Department as they do in Giuliani — the former mayor of New York, also a former US attorney, represented Trump in the Mueller probe and has done other work for the president in his personal capacity — the White House, and the State Department.

For one thing, Democrats are far more focused on whether the president was involved in trying to dig up dirt on Biden, a potential rival for the White House in 2020, versus the well-trodden ground of Trump’s attempt to undermine the Russia investigation, said Elliot Mincberg, a former chief counsel for the House Judiciary Committee.

“If the [Trump-Zelensky] phone call had only been about that, not about interference with the 2020 election, I don’t know that the whole thing would have raised the fuss that it did,” Mincberg, now a senior fellow at the liberal advocacy group People for the American Way, told BuzzFeed News. “It doesn't have quite the seriousness of essentially trying to get someone to do something in violation of campaign finance laws.”

The Justice Department has tried to distance Barr from Trump’s call with Zelensky and the firestorm that followed once details of the call became public. On Sept. 25, the day the White House released a written record of Trump’s call with Zelensky, DOJ spokesperson Kerri Kupec said in a statement that Barr had never spoken to Ukrainian officials about Biden “or any other subject,” and had not spoken with Giuliani about Biden “or anything related to Ukraine.”

Giuliani, on the other hand, worked with two associates, Lev Parnas and Igor Fruman, to meet with Ukrainian officials and urge them to investigate Biden and his family, as well as whether Ukrainian officials were involved in efforts to tilt the 2016 election in Hillary Clinton’s favor, according to an investigation published earlier this year by BuzzFeed News and the Organized Crime and Corruption Reporting Project. Giuliani’s interest in Biden stems from unsubstantiated allegations that Biden misused his position as vice president to interfere with a Ukrainian investigation into a company connected to his son, Hunter Biden.

Earlier this year, Barr tapped veteran federal prosecutor John Durham to oversee an investigation into the origins of the Russia probe, to the delight of Trump and congressional Republicans who have claimed it was rooted in anti-Trump bias. Trump and his allies have leaned into a variety of unproven conspiracy theories, including that there was illegal US surveillance of people connected to Trump’s campaign, and that Ukraine was involved in an effort to falsely pin blame on Russia for the hack of Democratic National Committee servers during the 2016 campaign. (The US intelligence community concluded that Russia was involved in the hack and orchestrated a widespread interference campaign.)

The Justice Department confirmed the existence of Durham’s probe, but hasn’t released details about the precise scope of his work, what direction he’s gotten from Barr, or a timeline for when he might finish. The Washington Post reported that Barr has personally urged foreign leaders to cooperate with Durham — Barr traveled with Durham to Italy to meet with senior government officials, communicated with British intelligence officials about Durham’s work, and asked Trump to encourage the Australian prime minister to provide assistance.

Kupec said in her Sept. 25 statement that “certain Ukrainians who are not members of the government have volunteered information to Mr. Durham, which he is evaluating.” Kupec didn’t elaborate. There’s been no confirmation that Durham is also looking into the Biden allegations, although Republican Sen. John Cornyn suggested in an Oct. 4 tweet that it was something the Justice Department was investigating.

Durham, whose career with the Justice Department goes back to the early 1980s, has a reputation as a “nonpartisan, diligent kind of guy,” said one former senior DOJ official familiar with Durham’s work, who agreed to speak with BuzzFeed News on condition of anonymity while the investigation is ongoing. Durham has experience overseeing high-profile, politically sensitive investigations, and the official said that would lend legitimacy to the work he’s doing now.

“He has an excellent reputation. He’s viewed as a nonpolitical professional who’s very thorough. I think if there’s a rap on him, it’s that he’s not the fastest in the world. At least going into this, people had a lot of confidence that he’s a straight shooter,” the official said.

The former official said their only concern was that Durham, a career prosecutor, would be analyzing a counterintelligence operation — the way prosecutors evaluate evidence in the context of a criminal investigation is different from how intelligence analysts might look at the same information, the former official said.

The Justice Department declined to open a full criminal investigation into Trump’s call with Zelensky, notwithstanding concerns expressed by the inspector general for the Intelligence Community that Trump’s request for help gathering information about Biden might have violated campaign finance laws. A senior DOJ official previously told reporters that they concluded the information discussed on the call wasn’t a “thing of value” that could be quantified.

House members may also have some reservations about trying to pull in the Justice Department while there are still active investigations. In addition to Durham’s probe, the Justice Department’s inspector general has an open investigation into the events leading up to the Russia investigation, specifically about how senior law enforcement officials authorized surveillance of former Trump campaign adviser Carter Page under the Foreign Intelligence Surveillance Act.

“Even if [Democrats] thought there was useful info, what would they ask for? ‘Please tell us what Durham is finding?’ They know the department isn’t going to give them that,” the former DOJ official said. “Right now they’re pulling at the State Department thread. Maybe they go someplace else further down the line.”

Another possible reason House Democrats aren’t looking at DOJ: They’re working with “not unlimited” resources and have to prioritize, Kerry Kircher, the former general counsel to the House of Representatives, wrote in an email to BuzzFeed News.

Trump’s July call with Zelensky was the subject of a whistleblower complaint that became public last month. Kircher wrote that it was logical that Democrats might try to follow the “roadmap” provided by the whistleblower’s complaint, which didn’t point as squarely at the Justice Department as it did at other arms of the executive branch.

The whistleblower, who has not been identified and wasn’t in the room for the call, not only relayed information about the substance of the July 25 call, but also described contacts between various senior State Department officials and Zelensky and other Ukrainian officials about what Trump had asked the Ukrainian president to do. The House Intelligence Committee released the complaint on Sept. 26.

“[T]he road map seems to lead most directly to the [White House] and the State Department, and that’s where the House’s (not unlimited) resources are being directed for now,” Kircher wrote in an email. “Whether the House issues subpoenas to DOJ probably depends on what the House learns from the witnesses from whom the House has been hearing (and what the press turns up).”